Skip to content

BUG: .str.replace repl string incorrectly parsed with pyarrow string dtype #57636

@jamesmyatt

Description

@jamesmyatt

Pandas version checks

  • I have checked that this issue has not already been reported.

  • I have confirmed this bug exists on the latest version of pandas.

  • I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

import pandas as pd

# Enable pandas 3.0 options
pd.options.mode.copy_on_write = True
pd.options.future.infer_string = True

pat = r"(?P<one>\w+) (?P<two>\w+) (?P<three>\w+)"
ser = pd.Series(['One Two Three', 'Foo Bar Baz'])

repl = r"\g<three> \g<two> \g<one>"
ser.str.replace(pat, repl, regex=True)

repl = r"\g<2>0"  # Note that this should be different from r"\20" according to the `re.sub` docs.
ser.str.replace(pat, repl, regex=True)

repl = r"\20"  # Should throw error since group 20 doesn't exist according to the `re.sub` docs.
ser.str.replace(pat, repl, regex=True)

Issue Description

The docs for .str.replace imply that the repl string can be anything that re.sub supports when regex=True. I think this is true for the current functionality, but isn't when using the pyarrow string dtype (pd.options.future.infer_string = True).

Specifically, the first 2 cases above throw the following error, but should work:

ArrowInvalid: Invalid replacement string: Rewrite schema error: '\' must be followed by a digit or '\'.

The last case above should throw, but instead is incorrectly treated as \g<2>0.

I guess that this is really an issue in the PyArrow backend rather than in pandas itself.

Expected Behavior

Matches pd.options.future.infer_string = False and matches re.sub.

Installed Versions

INSTALLED VERSIONS
------------------
commit                : f538741432edf55c6b9fb5d0d496d2dd1d7c2457
python                : 3.11.7.final.0
python-bits           : 64
OS                    : Windows
OS-release            : 10
Version               : 10.0.22621
machine               : AMD64
processor             : Intel64 Family 6 Model 154 Stepping 4, GenuineIntel
byteorder             : little
LC_ALL                : None
LANG                  : en_US.UTF-8
LOCALE                : English_United Kingdom.1252

pandas                : 2.2.0
numpy                 : 1.26.4
pytz                  : 2024.1
dateutil              : 2.8.2
setuptools            : 69.0.3
pip                   : 24.0
Cython                : None
pytest                : 8.0.0
hypothesis            : None
sphinx                : None
blosc                 : None
feather               : None
xlsxwriter            : None
lxml.etree            : None
html5lib              : None
pymysql               : None
psycopg2              : None
jinja2                : 3.1.3
IPython               : 8.21.0
pandas_datareader     : None
adbc-driver-postgresql: None
adbc-driver-sqlite    : None
bs4                   : 4.12.3
bottleneck            : 1.3.7
dataframe-api-compat  : None
fastparquet           : None
fsspec                : 2024.2.0
gcsfs                 : None
matplotlib            : 3.8.2
numba                 : 0.59.0
numexpr               : 2.9.0
odfpy                 : None
openpyxl              : None
pandas_gbq            : None
pyarrow               : 15.0.0
pyreadstat            : None
python-calamine       : None
pyxlsb                : None
s3fs                  : None
scipy                 : 1.12.0
sqlalchemy            : None
tables                : None
tabulate              : None
xarray                : None
xlrd                  : None
zstandard             : None
tzdata                : 2023.4
qtpy                  : None
pyqt5                 : None

Metadata

Metadata

Assignees

No one assigned

    Labels

    Arrowpyarrow functionalityBugStringsString extension data type and string data

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions